1. Field
Example embodiments relate to a method of forming an active region structure.
2. Description of Related Art
In general, a semiconductor device is fabricated to have a trench and a device isolation layer in a semiconductor substrate in order to limit active regions in the semiconductor substrate. The trench defines the active regions and is filled with the device isolation layer. The device isolation layer may securely insulate the active regions, as compared with an impurity diffusion region in the semiconductor substrate. However, with a reduction in the design rule of semiconductor devices, the dimensions of active regions are continuously decreasing. Thus, the dimensions of the active regions may approach the dimensions of the discrete elements disposed on the semiconductor substrate. As a result, the dimension of the trench may approach a limit of a semiconductor photolithography process and of a semiconductor etching process in the semiconductor substrate.